5.2 Troubleshooting Backup Performance

This section provides troubleshooting information that you can use to optimize the Backup Performance.

5.2.1 Identify Bottlenecks

TSATEST is a performance analyzer whose main purpose is to aid troubleshooting backup performance bottlenecks. TSATEST, reads data from SMS and discards it, simulating an infinite performance of the tape system. It also incorporates recommended processing models for backup applications and is used to distinguish performance bottlenecks.

If backup performance is poor, and TSATEST delivers as much as the backup application, then the bottleneck mostly points to the storage sub-system. For information on improving storage subsystem performance, see Storage Subsystem.

If backup performance is poor, but TSATEST displays very high throughput on the same storage sub-system, then bottleneck points to the backup application or the tape sub-system. For more information on backup applications and tape sub-systems, see Section 5.1, Prerequisites.

Monitor the disk throughput to determine the efficiency of the disk system to provide data for backup. As backup is an disk I/O bound problem, this helps to check if SMS delivers comparable performance as the disk system.

Fine-Tune Performance

Once the storage subsystem has been optimized, use the SMS tunable parameters to fine-tune performance. To accomplish and verify if the appropriate tuning parameter does influence performance, TSATEST can be used in various test runs in multiple combinations of TSAFS switches. This provides an inductive way towards detecting optimal sweet spots for your system. For more information on configuration parameters, see Section 5.3, Fine-Tuning SMS Performance.